The requirements for evacuating aircraft passengers quickly and safely from an aircraft emergency situation have become increasingly important as the size of aircraft and the number of passengers increases. Current federal regulations require evacuation of the aircraft in mere seconds. Emergency exit doors are provided along the aircraft fuselage in order to allow passengers to quickly evacuate the aircraft in an emergency situation. However, a number of passenger seats are located directly over the wing section of an aircraft. It is thus desirable to locate an emergency exit hatch immediately over the aircraft wing so that the passengers can leave the aircraft by stepping out onto the wing. Some evacuation slides are thus configured to be deployed directly over the aircraft wing. However, when an exit door is positioned over a wing of the aircraft, it is necessary to provide a safe way for passengers to travel from the wing surface to the evacuation slide configured to deploy over the wing. Such a passage may be a ramp that allows the passengers to safely move from the wing section onto the downwardly angled portion of the evacuation slide. Such ramps are typically inflatable ramps with a horizontal orientation that is used to connect the angled portion of the slide to the aircraft's wing. Ramps are often a separate component that is attached to the evacuation slide.
Inflatable ramps present a number of design challenges because the bottom surface of the ramp must interface with the curved and angled top surface of the wing. The inflatable ramps must safely and reliably support the weight of exiting passengers. The design of aircraft wings provides the upper wing surface with a substantial pitch. This means that the inflatable ramps are desirably adjusted to accommodate height and pitch differences. The general goal of the inflatable ramps is to prevent injury from passengers transitioning from the wing surface to the evacuation slide. It is also necessary that the inflatable ramps meet inflation speed requirements that are set for evacuation slides.
Current inflatable ramps use a single air chamber with an internal system of webs. The webs are formed of webbings and multiple layers of fabric located inside the single air chamber. The layers of fabric are intended to allow the inflatable ramp to conform to the upper surface of the wing and to present a level surface for evacuating passengers. However, these inflatable ramps are heavy and bulky. The trend in aviation design is to lower weight and bulk, and it is thus desirable to modify current inflatable ramps in order to reduce their weight and pack volume.